This paper discusses the application of power budget link in RFID systems with tags installed on vehicular windshield with polarized films. The performance of three tags on glasses with polarizing films and a circular polarized antenna is studied using full wave simulations and measurements. It is found that the mismatch effect due to the change impedance of the RFID antenna when the tag is placed on the windshield presents the main contribution in the budget losses and is the main responsible of the reading range reduction.
